Slot machines have been a part of online casinos since their inception in the mid 1990s. In order to enhance the appeal of online slot games software providers have introduced the concept of a wild symbol. This symbol was a designated symbol that would substitute for other symbols in order to make a winning combination. With the wild symbol winning combinations began to appear more frequently and slots players were happier. However, intense competition in the online casino arena drove software providers to packed more punch in the wild symbols. This article traces the evolution of the wild symbols in online slot games.

With the introduction of animations in online slot games, it was the wild symbol that usually had the most fascinating animation. In any event the wild symbol was the thematically most important symbol. In many online slots, the game title symbol is designated as the wild. Very often the wild symbol offers the highest line payouts. All in all, the wild symbol is given the pride of place among all the symbols.

Very soon the wild symbol began to increase the payouts in online slot games. The first act was giving it the property of a multiplier. If the wild symbol was used in making a winning combination the regular payout in the table would be multiplied. Doubling or tripling payouts through the wild symbol is fairly common. In some cases the multiplier is even greater. There are even online slot games in which each wild symbol in a winning combination independently multiplies the payouts.

Then wilds symbols began to take different forms. The most common is the stacked wild. The reels contain wild symbols grouped together in stacks. Therefore players may get two or even three wilds symbols in a reel. There are some online slot games with a large number of paylines that have four rows of symbols across the reels in which players can get wild symbols in stacks of four. The Microgaming online slot titled Summer Holiday is a perfect example. If these are stacks appear on the first or second reel then the payout potential of that spin is immense.

Another form of wild symbol is the expanding wild. In this case the wild symbol originally appears on one spot on the reel, but expands to cover the entire reel. A common scenario is the wild symbol depicting a face and after expansion forming a life size figure. This is visually more appealing than stacked wilds. In the Cryptologic online slot game Samba Nights the expanded wild presents a gyrating carnival dancer. Apart from its visual effectiveness the expanded wild also offers additional payout possibilities.

Many contemporary online slot games infuse additional properties in the wild symbol during the free spins bonus round. This often results in a bonanza for the player because any way these spins do not cost the player a cent. Different software providers have different schemes and different nomenclatures. A common concept is that once a wild symbol appears on a certain spot it remains fixed for the remainder of the free spins. The reels turn with each free spin and the symbols change, except for the wilds. If more wilds appear in subsequent spins they also become fixed. In this way the last few spins become very lucrative. This article has provided only a sample of how the wild symbol is being used by software providers. At the same time a word of caution is in order. The additional properties given to a wild symbol do not increase the average return in the slot game. The software provider makes other changes to level the playing field.